Pioneers, voyagers and the question

March 31, 2011|Ralph Couey

The news lately has been very bad. There is another shooting war in the Middle East, Japan and the earthquake, tsunami, and leaking radiation, and the ongoing soap opera in Washington. But in outer space, far from the din of humanity’s crises, a remarkable story continues.

In the 1970s, the United States launched four space probes. Their mission was the exploration of the sun’s family of planets. All four fulfilled their intended tasks flawlessly, returning stunning pictures and gigabytes of valuable data about the planets and the space between them. At the end of those missions, they were put on trajectories that would take them out of the solar system entirely; the first messengers of mankind.

Pioneer 10 was launched in March of 1972. Pioneer 11 left earth in April of 1973. Voyager 1 departed in 1977 and its brother, Voyager 2 roared away in 1978.

All four spacecraft, along with the usual retinue of scientific sensors, carry messages.

Pioneer 10 and 11 carry plaques made of gold anodized aluminum. The plaques carry pictures and symbols intended to educate extraterrestrials on where the probes came from, as well as something about the creatures that launched them.

On the plaques are a representation of the hydrogen molecule, a graphic picture of a man and woman, a map showing the location of the sun in relation to the center of our galaxy and 14 pulsars, and a silhouette of the spacecraft.

Whether an alien scientist would be able to decipher these etchings is still an open question, but as a first effort in interspecies communication, it’s not bad.

Voyager1 and 2 also left earth with messages, only not plaques but records. Carl Sagan, he of “Cosmos” fame, chaired a committee that selected a collection of sounds and images of life on this planet. Included are sounds of bird songs and whales, scientific images of earth’s location, the solar system, and human DNA.

Also included are images and sounds of a host of animal and plant life, as well as a portrait album of humans in all our colors, races, and cultures. Music from most cultures is included, one contribution being Chuck Berry’s “Roll Over Beethoven.” The pulsar map and hydrogen molecule from the Pioneer plaques were also included.

Etched on the record’s surface are the instructions for playback, including the picture of a stylus and the correct speed of rotation.

Again, whether another culture could decipher the record is unknown. But Dr. Sagan likened it to a time capsule, giving any space-faring civilization information that would answer for them the most profound question of intelligent beings: “Are we alone?”

That humans would do such a thing is an act of hope; hope that we will survive long enough to perhaps discover for ourselves the answer to that question.

All four are beyond the orbit of Pluto. Pioneer 10 stopped transmitting in 2003 and is currently 9.5 billion miles away headed towards the star Aldebaran. It should arrive in that vicinity in about two million years.

Pioneer 11 is 7.7 billion miles away and headed in the opposite direction, toward a group of stars known at the constellation Aquila, the Eagle, arriving there in about four million years.

Voyager 2 is 8.9 billion miles away, headed to the star Sirius. It’ll get there in 160,000 years.

Voyager 1 is the furthest, currently 10.9 billion miles away. It will arrive near the stars of constellation Camelopardis in 300,000 years.

The Pioneers have already gone silent and the Voyagers’ nuclear power sources will fail by 2020. Consequently, on arrival, they will be dead hulks. But even though the machinery will be dead, the plaques and records will still tell our story. And even if those scientists can’t decipher them, they’ll still know with certainty that they’re not alone.

But is anyone out there? As intelligent technological species go, we’re it that we know of. No other signals have been heard, no artifacts discovered. The distances between stars are immense, anywhere from hundreds to hundreds of millions of light years. If there are others out there, we may never know of them, nor they of us.

But that may be the defining legacy of the human race.

Not only that we spent our entire existence asking the unanswerable question, but that we fully expected an answer.